The constructor for Query_log_event allocated 2 bytes too few for
extra space needed by Query cache. (Not sure if this is reproducible
in practice, as there are often a couple of extra bytes allocated
for unused string zero terminators, but better safe than sorry).
CHEAP SQ: Valgrind warnings "Memory lost" with IN and EXISTS nested subquery, materialization+semijoin
Analysis:
The memory leak was a result of the interaction of semi-join optimization
with early optimization of constant subqueries. The function:
setup_jtbm_semi_joins() created a dummy temporary table "dummy_table"
in order to make some JOIN_TAB objects complete. Normally, such temporary
tables are freed inside JOIN_TAB::cleanup.
However, the inner-most subquery is pre-optimized, which allows the
optimization fo the MAX subquery to determine that its WHERE is TRUE,
and thus to compute the result of the MAX during optimization. This
ultimately allows the optimize phase of the outer query to find that
it WHERE clause is FALSE. Once JOIN::optimize finds that the result
set is empty, it sets zero_result_cause, and returns *before* it ever
reached make_join_statistics(). As a result the query plan has no
JOIN_TABs at all. Since the temporary table is supposed to be cleanup
via JOIN_TAB::cleanup, this never happens because there is no JOIN_TAB
for this table. Hence we get a memory leak.
Solution:
Whenever there are no JOIN_TABs, iterate over all table reference in
JOIN::join_list, and free the ones that contain semi-join temporary
tables.
WHEN KILLING
Suppose there is a query waiting for a lock. If the user kills
this query, then "Got error -1 when reading table" error message
must not be logged in the server log file. Since this is a user
requested interruption, no spurious error message must be logged
in the server log. This patch will remove the error message from
the log.
approved by joh and tatjana
Fixed by backport of:
------------------------------------------------------------
revno: 3402.50.156
committer: Jon Olav Hauglid <jon.hauglid@oracle.com>
branch nick: mysql-trunk-test
timestamp: Wed 2012-02-08 14:10:23 +0100
message:
Bug#13417754 ASSERT IN ROW_DROP_DATABASE_FOR_MYSQL DURING DROP SCHEMA
This assert could be triggered if an InnoDB table was being moved
to a different database using ALTER TABLE ... RENAME, while this
database concurrently was being dropped by DROP DATABASE.
The reason for the problem was that no metadata lock was taken
on the target database by ALTER TABLE ... RENAME.
DROP DATABASE was therefore not blocked and could remove
the database while ALTER TABLE ... RENAME was executing. This
could cause the assert in InnoDB to be triggered.
This patch fixes the problem by taking a IX metadata lock on
the target database before ALTER TABLE ... RENAME starts
moving a table to a different database.
Note that this problem did not occur with RENAME TABLE which
already takes the correct metadata locks.
Also note that this patch slightly changes the behavior of
ALTER TABLE ... RENAME. Before, the statement would abort and
return an error if a lock on the target table name could not
be taken immediately. With this patch, ALTER TABLE ... RENAME
will instead block and wait until the lock can be taken
(or until we get a lock timeout). This also means that it is
possible to get ER_LOCK_DEADLOCK errors in this situation
since we allow ALTER TABLE ... RENAME to wait and not just
abort immediately.
- Fixed code that was not ready for a major version number > 9
- Fixed test cases that assumed max major version number could be 9
Updated version number for depricated options (will be removed in a later commit)
VERSION:
Version number 10.0.0
client/mysqlbinlog.cc:
Added support for major version numbers > 9
cmake/mysql_version.cmake:
Added support for version numbers that is 0
mysql-test/r/comments.result:
Modified test to handle version number 100000
mysql-test/r/func_system.result:
Modified test to handle version number 100000
mysql-test/r/log_state.result:
Updated depricated error message
mysql-test/r/sp.result:
Modified test to handle version number 100000
mysql-test/r/subselect4.result:
Updated depricated error message
mysql-test/r/variables.result:
Updated depricated error message
mysql-test/suite/rpl/r/rpl_conditional_comments.result:
Modified test to handle version number 100000
mysql-test/suite/rpl/r/rpl_loaddatalocal.result:
Modified test to handle version number 100000
mysql-test/suite/rpl/t/rpl_conditional_comments.test:
Modified test to handle version number 100000
mysql-test/suite/rpl/t/rpl_loaddatalocal.test:
Modified test to handle version number 100000
mysql-test/suite/sys_vars/r/debug_basic.result:
Updated depricated error message
mysql-test/suite/sys_vars/r/engine_condition_pushdown_basic.result:
Updated depricated error message
mysql-test/suite/sys_vars/r/log_basic.result:
Updated depricated error message
mysql-test/suite/sys_vars/r/log_slow_queries_basic.result:
Updated depricated error message
mysql-test/suite/sys_vars/r/multi_range_count_basic.result:
Updated depricated error message
mysql-test/suite/sys_vars/r/rpl_recovery_rank_basic.result:
Updated depricated error message
mysql-test/suite/sys_vars/r/sql_big_selects_func.result:
Updated depricated error message
mysql-test/suite/sys_vars/r/sql_max_join_size_basic.result:
Updated depricated error message
mysql-test/suite/sys_vars/r/sql_max_join_size_func.result:
Updated depricated error message
mysql-test/t/comments.test:
Modified test to handle version number 100000
mysql-test/t/file_contents.test:
Modified test to handle version number 100000
mysql-test/t/func_system.test:
Modified test to handle version number 100000
mysql-test/t/parser_not_embedded.test:
Modified test to handle version number 100000
mysql-test/t/sp.test:
Modified test to handle version number 100000
sql/mysqld.cc:
Updated version number for depricated options (will be removed in a later commit)
sql/slave.cc:
Modified test to handle version number 100000
Better error messages
sql/sql_lex.cc:
Modified test to handle version number 100000 in comment syntax
sql/sys_vars.cc:
Updated version number for depricated options (will be removed in a later commit)
Analysis:
When a subquery that needs a temp table is executed during
the prepare or optimize phase of the outer query, at the end
of the subquery execution all the JOIN_TABs of the subquery
are replaced by a new JOIN_TAB that selects from the temp table.
However that temp table has no corresponding TABLE_LIST.
Once EXPLAIN execution reaches its last phase, it tries to print
the names of the subquery tables through its TABLE_LISTs, but in
the case of this bug there is no such TABLE_LIST (it is NULL),
hence a crash.
Solution:
The fix is to block subquery evaluation inside
Item_func_like::fix_fields and Item_func_like::select_optimize()
using the Item::is_expensive() test.
Problem
========
Replication breaks in the cases if the event length exceeds
the size of master Dump thread's max_allowed_packet.
The reason why this failure is occuring is because the event length is
more than the total size of the max_allowed_packet, on addition of the
max_event_header length exceeds the max_allowed_packet of the DUMP thread.
This causes the Dump thread to break replication and throw an error.
That can happen e.g with row-based replication in Update_rows event.
Fix
====
The problem is fixed in 2 steps:
1.) The Dump thread limit to read event is increased to the upper limit
i.e. Dump thread reads whatever gets logged in the binary log.
2.) On the slave side we increase the the max_allowed_packet for the
slave's threads (IO/SQL) by increasing it to 1GB.
This is done using the new server option (slave_max_allowed_packet)
included, is used to regulate the max_allowed_packet of the
slave thread (IO/SQL) by the DBA, and facilitates the sending of
large packets from the master to the slave.
This causes the large packets to be received by the slave and apply
it successfully.
sql/log_event.cc:
The max_allowed_packet is not evaluated to the new option
slave_max_allowed_packet after the fix.
sql/log_event.h:
Added the new option in the log_event.h file.
sql/mysqld.cc:
Added a new option to the server.
sql/slave.cc:
Increasing the session max_allowed_packet to a large value,
i.e. not taking global(max_allowed) into consideration, for the slave's threads.
sql/sql_repl.cc:
The dump thread's max_allowed_packet is set to the upper limit
which makes it independent and it now reads whatever gets
logged in the binary log.
WHEN KILLING
Suppose there is a query waiting for a lock. If the user kills
this query, then "Got error -1 when reading table" error message
must not be logged in the server log file. Since this is a user
requested interruption, no spurious error message must be logged
in the server log. This patch will remove the error message from
the log.
approved by joh and tatjana
- Adding %M my_sprintf() modifier that prints error number - system-error-text
- Modified mysys, mysql_client and SQL error messages to use %M instead of %d
- Added my_strerror()
Updated handler errors to 5.6 error numbers
Updated text for a few error messages (to match 5.6)
Increased length of command name in error output
extra/comp_err.c:
Added support for %M
include/my_base.h:
Updated handler errors to 5.6 error numbers
include/my_sys.h:
Added my_strerror()
libmysql/errmsg.c:
Updated error messages to use %M
mysql-test/r/errors.result:
Updated result as error message have changed
mysql-test/r/innodb_mysql_sync.result:
Updated result with text for errno
mysql-test/r/myisam-system.result:
Updated result with text for errno
mysql-test/r/myisam.result:
Updated result as error message have changed
mysql-test/r/myisampack.result:
Updated result with text for errno
mysql-test/r/mysql.result:
Updated result with text for errno
mysql-test/r/mysql_upgrade.result:
Updated result with text for errno
mysql-test/r/partition_datatype.result:
Updated result as error message have changed
mysql-test/r/partition_innodb_plugin.result:
Updated result with text for errno
mysql-test/r/ps_1general.result:
Updated result with text for errno
mysql-test/r/trigger.result:
Updated result with text for errno
mysql-test/r/type_bit.result:
Updated result as error message have changed
mysql-test/r/type_bit_innodb.result:
Updated result as error message have changed
mysql-test/r/type_blob.result:
Updated result as error message have changed
mysql-test/suite/archive/archive.result:
Updated result with text for errno
mysql-test/suite/binlog/r/binlog_index.result:
Updated result with text for errno
mysql-test/suite/binlog/r/binlog_ioerr.result:
Updated result with text for errno
mysql-test/suite/csv/csv.result:
Updated result with text for errno
mysql-test/suite/federated/federated_bug_35333.result:
Updated result with text for errno
mysql-test/suite/innodb/r/innodb-create-options.result:
Updated result with text for errno
mysql-test/suite/innodb/r/innodb-index.result:
Updated result with text for errno
mysql-test/suite/innodb/r/innodb-zip.result:
Updated result as error message have changed
mysql-test/suite/innodb/r/innodb.result:
Updated result with text for errno
mysql-test/suite/innodb/r/innodb_bug21704.result:
Updated result with text for errno
mysql-test/suite/innodb/r/innodb_bug46000.result:
Updated result with text for errno
mysql-test/suite/innodb/r/innodb_bug53591.result:
Updated result as error message have changed
mysql-test/suite/innodb/r/innodb_corrupt_bit.result:
New error numbers
mysql-test/suite/innodb/r/innodb_prefix_index_liftedlimit.result:
Updated result as error message have changed
mysql-test/suite/innodb/t/innodb-create-options.test:
Added regexp to avoid system error text
mysql-test/suite/innodb/t/innodb-zip.test:
Added regexp to avoid system error text
mysql-test/suite/maria/maria-recovery2.result:
Updated supression rule
mysql-test/suite/maria/maria-recovery2.test:
Updated supression rule
mysql-test/suite/maria/maria.result:
Updated result as error message have changed
mysql-test/suite/parts/r/partition_bit_innodb.result:
Updated result as error message have changed
mysql-test/suite/parts/r/partition_bit_myisam.result:
Updated result as error message have changed
mysql-test/suite/percona/percona_innodb_fake_changes.result:
Updated result with text for errno
mysql-test/suite/perfschema/r/dml_cond_instances.result:
Updated result as error message have changed
mysql-test/suite/perfschema/r/dml_events_waits_current.result:
Updated result as error message have changed
mysql-test/suite/perfschema/r/dml_events_waits_history.result:
Updated result as error message have changed
mysql-test/suite/perfschema/r/dml_events_waits_history_long.result:
Updated result as error message have changed
mysql-test/suite/perfschema/r/dml_ews_by_instance.result:
Updated result as error message have changed
mysql-test/suite/perfschema/r/dml_ews_by_thread_by_event_name.result:
Updated result as error message have changed
mysql-test/suite/perfschema/r/dml_ews_global_by_event_name.result:
Updated result as error message have changed
mysql-test/suite/perfschema/r/dml_file_instances.result:
Updated result as error message have changed
mysql-test/suite/perfschema/r/dml_file_summary_by_event_name.result:
Updated result as error message have changed
mysql-test/suite/perfschema/r/dml_file_summary_by_instance.result:
Updated result as error message have changed
mysql-test/suite/perfschema/r/dml_mutex_instances.result:
Updated result as error message have changed
mysql-test/suite/perfschema/r/dml_performance_timers.result:
Updated result as error message have changed
mysql-test/suite/perfschema/r/dml_rwlock_instances.result:
Updated result as error message have changed
mysql-test/suite/perfschema/r/dml_threads.result:
Updated result as error message have changed
mysql-test/suite/perfschema/r/misc.result:
Updated result with text for errno
mysql-test/suite/perfschema/r/privilege.result:
Updated result with text for errno
mysql-test/suite/rpl/r/rpl_EE_err.result:
Updated result with text for errno
mysql-test/suite/rpl/r/rpl_binlog_errors.result:
Updated result with text for errno
mysql-test/suite/rpl/r/rpl_drop_db.result:
Updated result with text for errno
mysys/errors.c:
Updated error messages to use %M
Changed all errors to use Errcode: consistenly
mysys/my_handler_errors.h:
Updated handler errors to 5.6 error numbers
sql/share/errmsg-utf8.txt:
Updated error messages to use %M
sql/sys_vars.cc:
Added error number to ER_EVENT_SET_VAR_ERROR
strings/my_vsnprintf.c:
Added %M my_sprintf() modifier that prints error number - system-error-text
Simplify code
Movied common code to function
Removed some casts that was not necessary when reading integer/unsigned int stored in longlong
Added my_strerror()
unittest/mysys/my_vsnprintf-t.c:
Added testing of %M
Analysis:
The fix for lp:944706 introduces early subquery optimization.
While a subquery is being optimized some of its predicates may be
removed. In the test case, the EXISTS subquery is constant, and is
evaluated to TRUE. As a result the whole OR is TRUE, and thus the
correlated condition "b = alias1.b" is optimized away. The subquery
becomes non-correlated.
The subquery cache is designed to work only for correlated subqueries.
If constant subquery optimization is disallowed, then the constant
subquery is not evaluated, the subquery remains correlated, and its
execution is cached. As a result execution is fast.
However, when the constant subquery was optimized away, it was neither
cached by the subquery cache, nor it was cached by the internal subquery
caching. The latter was due to the fact that the subquery still appeared
as correlated to the subselect_XYZ_engine::exec methods, and they
re-executed the subquery on each call to Item_subselect::exec.
Solution:
The solution is to update the correlated status of the subquery after it has
been optimized. This status consists of:
- st_select_lex::is_correlated
- Item_subselect::is_correlated
- SELECT_LEX::uncacheable
- SELECT_LEX_UNIT::uncacheable
The status is updated by st_select_lex::update_correlated_cache(), and its
caller st_select_lex::optimize_unflattened_subqueries. The solution relies
on the fact that the optimizer already called
st_select_lex::update_used_tables() for each subquery. This allows to
efficiently update the correlated status of each subquery without walking
the whole subquery tree.
Notice that his patch is an improvement over MySQL 5.6 and older, where
subqueries are not pre-optimized, and the above analysis is not possible.
Problem: mysqlbinlog exits without any error code in case of
file write error. It is because of the fact that the calls
to Log_event::print() method does not return a value and the
thus any error were being ignored.
Resolution: We resolve this problem by checking for the
IO_CACHE::error == -1 after every call to Log_event:: print()
and terminating the further execution.
client/mysqlbinlog.cc:
- handled error conditions during event->print() calls
- added check for error in end_io_cache()
mysys/my_write.c:
Added debug code to simulate file write error.
error returned will be ENOSPC=> error no space on the disk
sql/log_event.cc:
Added debug code to simulate file write error, by reducing the size of io cache.
Optimizator fails using index with ST_Within(g, constant_poly).
per-file comments:
mysql-test/r/gis-rt-precise.result
test result fixed.
mysql-test/r/gis-rtree.result
test result fixed.
mysql-test/suite/maria/r/maria-gis-rtree-dynamic.result
test result fixed.
mysql-test/suite/maria/r/maria-gis-rtree-trans.result
test result fixed.
mysql-test/suite/maria/r/maria-gis-rtree.result
test result fixed.
storage/maria/ma_rt_index.c
Use MBR_INTERSECT mode when optimizing the select WITH ST_Within.
storage/myisam/rt_index.c
Use MBR_INTERSECT mode when optimizing the select WITH ST_Within.
Analysis:
-------------
If server is started with limit of MAX_CONNECTIONS and
MAX_USER_CONNECTIONS then only MAX_USER_CONNECTIONS of any particular
users can be connected to server and total MAX_CONNECTIONS of client can
be connected to server.
Server maintains a counter for total CONNECTIONS and total CONNECTIONS
from particular user.
Here, MAX_CONNECTIONS of connections are created to server. Out of this
MAX_CONNECTIONS, connections from particular user (say USER1) are
also created. The connections from USER1 is lesser than
MAX_USER_CONNECTIONS. After that there was one more connection request from
USER1. Since USER1 can still create connections as he havent reached
MAX_USER_CONNECTIONS, server increments counter of CONNECTIONS per user.
As server already has MAX_CONNECTIONS of connections, next check to total
CONNECTION count fails. In this case control is returned WITHOUT
decrementing the CONNECTIONS per user. So the counter per user CONNECTIONS goes
on incrementing for each attempt until current connections are closed.
And because of this counter per CONNECTIONS reached MAX_USER_CONNECTIONS.
So, next connections form USER1 user always returns with MAX_USER_CONNECTION
limit error, even when total connection to sever are less than MAX_CONNECTIONS.
Fix:
-------------
This issue is occurred because of not handling counters properly in the
server. Changed the code to handle per user connection counters properly.
- In JOIN::exec(), make the having->update_used_tables() call before we've
made the JOIN::cleanup(full=true) call. The latter frees SJ-Materialization
structures, which correlated subquery predicate items attempt to walk afterwards.
- Don't try to produce plans after JOIN::cleanup() has been called, because:
= JOIN::cleanup leaves data structures in partially-cleaned state
= Walking them is hazardous (see this bug), and has funny effects
(See previous commits, "Using join cache" may or may not be shown)
= Changing data structures to be persisted may cause unwanted side effects
- The consequence is that SHOW EXPLAIN will show "Query plan already deleted" when e.g.
reading data after filesort.
Details:
- Archive storage engine file access were not instrumented and thus
were not shown in PS tables.
Fix:
- Added instrumentation code by using PS Apis for I/O.
